Quench chute for heat-treating furnaces



Oct; 8, 1940,

E. K. HANSEN QUENCH CHUTE FOR HEAT-TREATINGFURNACES Filed March 4, 19393 Sheets-Sheet 1 ATTORNEY WITNESSES; 4%.

Oct. 8, 1940. E. K. HANSEN QUENCH CH UTE FOR HEAT-TREATING FURNACESFiled March 4, 1939 3 Sheets-Sheet 2 I INVENTOR E/merfhwzserz.

WITNESSES:

ATTORNEY Oct. 8, 1940. E, HANSEN 2,217,441

QUENCH CHUTE FOR HEAT-TREATING FURNACES Filed March 4, 19.39 3Sheets-Sheet 3 m2 as 9 m2 /44 98 86 8 Egg WITNESSES:

INVENTOR Eimerflifiaflsen.

pa xZM MK F W ATTORNEY Elmer K. Hansen,

My invention relates to QUENoH onu'rn FOR HEAT-TREATING FURNACESWestinghouse Edgewood, Pa, assignor to Electric & Manufacturing (Jmpany,East Pittsburgh, Pa., a corporation of Pennsylvania Application March 4,1939, ,Serial No. 259,784

8 Claims.

heat-treating furnaces of the type having a quench-opening thru whicharticles, heat-treated in the furnace, are directed into a quench-tankfor quenching, and is more particularly applicable where a plurality ofdifferent quenches are care of different kinds of desired, either fortaking articles heat-treated separately in the furnace, or for providingdifferent quenches at different times for the same article.

A furnace of the character to which my invention is particularlyapplicable usually has the quench-opening in the wall of the furnace,most commonly at the end of the bottom wall, and

the heat-treated articles quench-opening into a quen low the opening.

pass through the ch-tank disposed be- In common practice where more thanone type of quench is required, it is customary to provide either tankwhich is drained and a single quenchrefilled with the desired quenchingliquid with every change of quench, or the quench-tank is provided witha plurality of sections, any one of which can be placed under aquench-chute by moving the quench-tank, the above the tank toquench-chute terminatin permit free movement of the latter, or someother equivalent expedient is employed. However, it is frequentlydesirable that the quench-chute terminate below level of thequench-liquid in the quench-tank, particularly in furnaces employing aprotective atmosphere to envelop the articles being heat-treated. Suchconstruction is essential if undue contamination of the protectiveatmosphere by excessive leakage of air into the furnace opening is to beprevented. tures heretofore employed from one quenching liquid by way ofthe quench- The common strucpermit the change to another in such casesonly by awkward manipulations or unsatisfactory methods.

In accordance with my invention, I provide a sectionalized quench-chutewith the ends of the sections so constructed tight sealing means betweenthe sections.

be moved relative to each different sections can as to provide a gas-The other in such a manner that the lowermost part of the chute can beraised above the top of the quench-tank, whereupon the quench-tank canbe moved without chute. The quench-tank c interference with the quenchanbe provided with a plurality of compartments each having its ownquenching liquid, and

when the compartment containing the proper quenching medium isunderneath the quench-opening,

quench-chute may be move the sections of the d back into working icallycollapsible sections.

Inasmuch as the quench-chute and quenchtank for heat-treating furnacesare generally disposed below the floor level, I provide, infurtheranceof my invention, an operating means above the floor level foroperating the collapsible 10 sections of the chute. By providing powermeans for moving the quench-tank, a change in quenching liquid can beaccomplished easily and simply, and without any appreciable loss oftime. However, in its operative position, the quenchchute extends belowthe level of the quenching liquid in the quench-tank, and, therefore, asa safety measure, I control the quench-tank moving means so that itcannot move the quenchtank unless the quench-chute has been 001- lapsedto a position in which it will not interfere with movement of the tank.Moreover, in a furnace provided with automatic charge-conveying means inits heating chamber, I can interlock the driving means for the conveyorso that it, too, will be inoperative to dump heat-treated articlesthrough the quench-opening while the quench-tank is being moved.

My invention involves the foregoing general objects and also involvesmany features of 0011- '30 struction for the quench-chute which I deemnovel and important. These novel features and other objectives of myinvention will be apparent from the following description, taken inconjunction with drawings in which like numerals .35 refer to like partsand in which,

Figure 1 is a schematic cross-sectional view of a quench-type furnaceembodying my invention;

Fig. 2 is a plan view diagrammatically showing on a condensed scale aquench-tank of two com- 40 partments;

Fig. 3 is a sectional view on an enlarged scale of my novelquench-chute;

Fig. 4 is an elevational view transverse to Fig.

3 partly in section, of the quench-chute of Fig. 3;

Fig. 5 is a top plan view of the quench-chute of Fig. 3;

Fig. 6 is an exploded, perspective view of the bottom elements of theupper section of the quench-chute of Fig. 3 and Fig. 7 is a schematicelectric wiring diagram showing the interlock control for the movingmeans for the quench-tank and the conveyor in the furnace.

Referring to Figure 1, a furnace 2 is supported upon suitable structuralmembers 4 resting or imbedded in floor 6 provided with cavities 8 and Ibelow each end of the furnace.

The furnace 2 may be of any appropriate type having a top wall l2, abottom wall i l, a frontend wall l6, a rear-end wall l8 and appropriateside walls; the walls defining a heating chamber 26. The walls areconstructed of suitable refractory and insulating substances as iscommon in the art, and the front wall is provided with an entranceopening 22, while the bottom wall is' rovided at the rear thereof with aquenchopening 26 defined by a suitable quench-duct 26, preferably of aheat resisting alloy. Disposed Within the furnace is anysuitableconveyor 28, here shown of the continuously-moving type, driven by amotor 36 through power transmitting means 32.

It is obvious that in the operation of the structure thus far described,articles to be heat-treated are disposed upon'the conveyor 28 at theentrance opening 22, and are moved by the conveyor through the heatingchamber 26 until they are dropped off the rear end of the furnacewhereupon they fall through the quench-duct 26. In order to keep theconveyor taut a suitable stretching means 36 is disposed in the cavityW, in accordance with well known practice. The furnace may be heated byany suitable heating means (not shown) which may be either of theelectrical resistor type or the gas-fired radiant tube type, or of anyof the more common means.

The particular furnace 2 is adapted for heattreating of the articlesupon the conveyor 26 in a protective gaseous atmosphere and to this endsuitable protective-gas inlets 36 are provided for conveying the gasesto the heating chamber 26, and the walls of the furnace are encased in agas-impervious metallic shell 38.

The heattreated articles falling through quench-duct 26 continue througha quenchchute indicated in its entirety by the reference character 40,and then drop into a quench-tank 62. The quench-chute and quench-tankaredisposed in the cavity 6 on the base floor of which are rails 44. Thequench-tank 62 is provided with shafts 46 upon which are journaledwheels 48 riding upon the rails 64 so that the quenchtanks may be easilymoved from one position to another.

' The quench-tank moving means comprises a reversible electric motor 56having a shaft 52 to which is attached a worm gear 54. The worm 54engages a gear 56 on one end of a shaft 58 suitably supported on thebottom of cavity 8. The shaft 58 is preferably a worm which engages anut 60 depending from the bottom of the quench-tank 42. It is manifestthat by the foregoing means, the quench-tank 42 will be moved in onedirection when the motor 52 rotates in a fixed direction, and that thequenchtank will move in an opposite direction when the rotation of themotor 56 is reversed. v

The tank 42 is preferably provided with a plurality of compartments,and, as shown in Fig. 2,"may have two compartments 62 and 64 is providedwith its own quenching liquid, and has disposed therein a conveyor 6?for conveying out of the quench-tank any articles or charges that havedropped therein.

separated by a partition '66. Each compartment A suitable guiding means67' may be disposed 'sition underneath the quench-duct.

in each tank for directing the articles dropping into the tank ontotheir respective conveyors.

As may be observed from Fig. 1, the quenchchute 46 comprises twotelescopically collapsible and extensible sections 63 and 10. In theextended position of the chute, the bottom edge of the section 76 isbeneath the level of the quenching-liquid in the quench-tank 42, and itis manifest, therefore, that if the quench-tank is to be moved, thesection 70 must be raised out 7 of the path of the partition 66.

Referring more particularly to Figs. 3 through 6, in accordance with myinvention, the upper section 6% of the quenchchute comprises a slantedinner-tube l2 encompassed by a larger outer-tube it, both, in thisparticular embodiment, being of rectangular section. A bottom closureplate 76 and a top closure plate 16 enclose the space between the innerand outer tubes l2 and M respectively. In view of the slantingdisposition of the tube 12, the plate 18 has an aperture conforming tothe size of the tube 12 and disposed toward one side of this plate,while the plate "l6 has a similar aperture conforming to the oppositeend of the tube l2 and also disposed to one side of the plate 16.

The plates 76 and 78 and the tubes 12 and 14 are preferably Weldedwater-tight, so that the space 86 confined by these elements may serveas a water-jacket for cooling the quench-tube ii. To this end, a waterinlet 82 and a wateroutlet 84 are provided for the space 80, and it maybe observed that the inlet tube 82 is disposed angularly to terminatesomewhat centrally of the longer dimension of the quench-chute,

and that the water-outlet 84 is on the opposite side and near the topthereof so that an eflicient water circulating system within the space80 is obtained.

- The upper plate 18 is made somewhat larger than the area of tube 74 toprovide flanges 86 by which the quench-chute may be secured to thefurnace proper. To this end, the flanges 86 have a plurality ofapertures 88 completely around their rectangular periphery, and bolts 90extend thru the shell 38 and suitable apertures therein to provide inconjunction with nuts 92 fastening means for securing the section 68 inproper po- A gasket 93 may be interposed between the flanges 86 and theshell 38 for a gas-tight joint.

The lower section 16 of the chute 46 has a cross-section similar to thatof the outer-tube M of the upper section, but of a larger encompassingsize so that it may be telescopically col- 'lapsible about the uppersection 68. As aconvenient means for raising and lowering the lowersection the last is provided with a plurality of spaced lugs 9 onopposite sides thereof, and secured to the upper part of the lowersection, while a plurality of stub shafts 96 are similarly disposed onthe upper part of the upper section 68. Sheaves 68 are loosely mountedon the shafts 96 and are maintained in position thereon by cotter pinsHill or the like. Cables I62 are fastened to 1c lugs 9-6 and pass overthe sheaves 98, from whence they extend horizontally to sheaves I64,

preferably disposed at the side of the furnace. The cables are then runupwardly over appropriate guiding sheaves N36 to a manually-operabledrum 568, secured and rotatably mounted above the level. of the floor 6.The drum is provided 'With a handle H6 by which it may be rotated towind or unwind cables H12 wherbey the lower sectionit may be raised orlowered in an evident manner. In order to latch the parts in position, alatching means comprising a ratchet wheel I I2 and a latch I I4 isprovided, the ratchet wheel I I2 being secured to the drum I08 and thelatch pivoted in a proper position for engaging the ratchet wheel forlatching the drum.

My novel punch-chute is designed as aforesaid, for particularapplication to furnaces employing a protective gaseous atmosphere in itsheating chamber, and to prevent either an excessive loss of atmosphereor undue contamination of the at-- mosphere, I provide my chute with anovel construction which results in a gas-tight sealing means betweenthe collapsible sections. As more particularly shown in Fig. 6, thelower plate I6 has a plurality of tapped apertures IIS spaced about theperiphery thereof, and a lower, apertured, trough-member II8 includes abase plate I20 having apertures I2I positioned to cooperate with theapertures I I6. The base plate I20 of the trough-member II8 is of a sizesomewhat larger than the outside dimensions of the tube I4 of the upperchute section, butsomewhat smaller than the inside dimensions of thetube III of the lower chute section to provide a rigid securing means bywhich the base I20 can be secured to the plate I6, as more particularlyshown in Figs. 4 and 6. Extending upwardly from the outer edge of thebase I20 is an up-standing side I22 so thatwhen the trough-member II8isv secured to the upper section 08 of the quench-chute, in effect atrough I24 is provided which may be filled with oil or any other sealingmedium. The trough-member II8, obviously, is secured to the base plate16 by means of screws or bolts I26 fitting through the apertures I2I inthe base plate I20 and secured in the threaded apertures N6 of the baseplate I6. A suitable gasket I20 is interposed between the two baseplates I6 and I20 to assure a gas and oil tight joint.

To complete the seal, the lower section of the quench-chute isintegrally provided with an inwardly turned-over lip comprising ahorizontal portion I30 and a downwardly-extending lip portion I32. Thelip portion I32 is of a size to fit within the trough I24 which, whenfilled with a sealing medium such as oil, cooperates with theoverhanging lip portion I32 of the lower section I0 to provide agas-tight seal between the cooperating ends of the collapsible sectionsof the chute. Moreover, because part of the water jacket is interposedbetween the oil seal and the tube I2 which may be at a high temperaturedue to the heated articles falling therethrough, the oil in the sealwill be kept relatively cool so that its efficacy as a seal will not bedestroyed by deterioration or decomposition due to excessive heating.The life of the oil is accordingly practically unlimited.

In addition to serving as part of the seal, the trough-member H8 canalso act as a support for the lower section I0 of the chute. In suchcase the cables I22 are used only in the capacity of part of theoperating means for the lower section of the chute. In this case, thelip I32 may rest upon the base member I20, or, alternatively, thehorizontal portion I30 of the section 10 may rest on the up-standing legI22 of the trough-member II8.

It should be observed that by securing the trough-member II8 to theclosure plate 16 as I do, rather than having it integral with the tubeI4, the respective sections 68 and I0 can be readily assembled into thecomplete chute, or the lower section removed without disturbing theupper section 68 or any of the parts protruding therefrom. In thepreferred manner of assembling and dismantling lower section I0, it isplaced in a position about the upper section 68 leaving ample spacebeneath the two for securing or removing the trough-member I I8 to orfrom the plate 16 as the case may be.

In accordance with common practice for construction of furnaces of thequench type that employ a protective atmosphere, I provide gas-inletmeans I40 adapted to convey the gases of the protective atmosphere tothe furnace at spaced points approximately along the bottom of thequench-duct 26. Any suitable number of such inlet pipes I 40 may beprovided. The gas admitted through the pipes I40 usually serve as acurtain to prevent any fumes from the quench rising into the heatingchamber. Moreover, a plurality of exhaust pipes I42 may be provided atthe upper part of the upper section of the quenchchute and below the gasinlets I40 for exhausting whatever fumes that find their way into thechute. Usually with proper spacing of the pipes, a small suction head ofapproximately of water is sufiicient to prevent fumes from entering thefurnace, and at the same time no appreciable amount of the protectiveatmosphere will be drawn into the exhaust pipes along with the fumes.

It may be observed that in accordance with the cooling liquid at thebottom of the water jacket. The primary purpose of this construction isto provide an unobstructed path for raising the lower section I0 aboutthe upper section 68 since, if the water inlet pipe were positioned atthe bottom of the section 68, as is usual, the lower section would notthen be free to rise. If desired, the bottom of the section I0 may beflared as shown at I44 adding rigidity to the bottom section, but thisis obviously an optional detail of construction.

It may therefore be observed that in accordance with the objects andfeatures of my invention, I have provided a collapsible quench-chuteWhose lower section I0 may be raised above the top of the tank 42, sothat the tank may be moved with either compartment 02 or compartment 64placed under the chute. All that is necessary is that the drum I08 befirst wound up to raise the chute, the operating means of the motor ofthe quench-tank then operated to position the desired compartment underthe chute, and then the latch II4 may be released to permit the lowersection I0 to drop.

When the chute is in collapsible position, it is desirable that theconveyor be incapable of discharging articles for quenching, and whenthe chute is in extended position, it is desirable that the quench-tankbe incapable of moving and possibly damaging the extended quench-chute.In order to accomplish these purposes a multiplepole switch I46 isprovided which is operated by the lower section I0 of the chute whenthat section is in raised or collapsible position. Referring to thewiring diagram of Fig. 7, it may be observed that the conveyor motor 30is energized from a suitable source of power I48 through a controlswitch I50 and contactors I52 of the switch I46. The contactors I52 arein circuitclosing position whenever the horizontal portion I30 of thelower section 10 does not engage h the operating member i53 of theswitch M6, that is, whenever the section 70 is extended. Accordingly, itis manifest that the conveyor motor 30 may be energized by closing theswitch I 56 whenever the quench-chute is in its proper position in thequench-tank, but cannot be energized even if the control switch I552 isclosed, whenever the lower section Til is in raised position whereby itopens the energizing circuit to the motor 30 at the contactors I52.

Similarly, the contactors E54 operated by the control switch MB controlthe operation of the tank-moving motor 59. However, these contactorshave a position reversed to that of the contactors I52, being incircuit-closing when'the section 15) is in raised or collapsed positionand in circuit-opening position otherwise. Thus, the power supply forthe motor 58 coming from the source of energy 556 passes through a maincon-. trol switch I58 through the contactors I54 and through a reversingswitch 8%. When the lower section N3 of the quench-chute is in aposition other than in raised position, as, for example, projectingsomewhat into the quench-tank, the motor 50 cannot be energized sincethe contactors H54 are then in circuit-opening position. However, if thelower section 10 be raised to operate the switch M6, the contactors I54will be moved against the pressure of spring I62 to circuitclosingposition. If the main switch I58 is closed then by suitable operation ofthe reversing switch N59, to energize motor 50, either compartment 6201M of the quench-tank may be placed under the quench-opening 24.Manifestly, limit switches may be applied to further control the motor50 in accordance with the position of the quench-tank so as to assurethat the tank will be properly positioned under the quench-opening forwhichever of its compartments is selected to be employed for quenching.

While I have illustrated my invention in accorclance with a preferredembodiment thereof, it is manifest that many modifications and changesmay be made therein and equivalents substituted without departing fromthe spirit of my invention. Accordingly, I desire that the appendedclaims be given their broadest interpretation and limited by the priorart.

I claim as my invention:

1. A quench-chute comprising a pair ofv nested tubes, top and bottomclosure plates defining a cooling jacket between said tubes, said platesbeing apertured to correspond to the inner of said nested tubes, and acorrespondingly-apertured flanged plate removably secured to said bottomplate and of larger periphery and having an upstanding flange whereby toform a sealingtrough with the outer of said tubes.

2. A quench-chute comprising a slanted inner tube and a surroundingsubstantially vertical outer tube, top and bottom cover means betweenthe ends of said tubes and sealed thereto thereby defining a coolingjacket, water inlet and outlet means to said jacket, an upwardly-flangedplate having an opening therein sufficient to encompass the loweropeningoi the said inner tube, and means to secure said platesubstantially at the bottom of said chute whereby to form a sealingtrough with said outer tube.

3. A quench-chute comprising a pair of telescopically collapsiblesections, one of said sections comprising a pair of nested tubes, topand bottom closure plates defining a cooling jacket between said tubes,said plates being apertured to correthereby provide a seal, cable meanssecured to the upper end of said second section and passing over saidsheaves, and means to operate said cables to raise and lower said secondsection.

4. A quench-chute comprising an upper section having a pair of nestedtubes, top and bottom closure plates defining a cooling jacket betweensaid tubes, said chute also comprising a lower section telescopicallycollapsible about said upper section, and liquid inlet and outlet meansto said jacket, the last said means being disposed near the top of saidupper section whereby not to interfere with raising of the lowersection.

5. A quench-chute comprising an upper section having a pair of nestedtubes, top and bottom closure plates defining a cooling jacket betweensaid tubes, said .chute also comprising a lower section telescopicallycollapsible about said upper section, liquid inlet means to said jacket,disposed near the top of said upper section and including a tube insidesaid jacket having a discharge end near the bottom of said jacket, andliquid outlet means for said jacket disposed near the top of said uppersection whereby the two last-recited means do not interfere with raisingof said lower section.

,6. A quench-chute comprising an upper section having a pair of nestedtubes and means enclosing the space between said tubes to provide acooling jacket, said chute also comprising a movable lower sectiontelescopically collapsible and extensible about said upper section,liquid inlet means to said jacket comprising a pipe dischargingsubstantially at the bottom of said jacket, having all of its portionsout. of the path of the movement of said lower section, and liquidoutlet means for said cooling jacket.

7. A quench-chute comprising a pair of telescopically collapsible andextensible sections, one of said sections being an upper section, saidupper section comprising an inner chute tube and cooling jacket for saidtube, a second of said telescopically collapsible and extensiblesections com-' prising a lower section, and cooperating meanssubstantially at the bottom of said upper section and at the top of saidlower section providing a gas-seal between said sections, said sealbeing disposed next to said cooling jacket whereby said coolingjacketalso cools said seal.

8. A quench-chute comprising an upper section having an inner tube andan outer tube, said tubes being nested, and having means enclosing thespace between said tubes to provide a cooling jacket, said .chute alsocomprising a lower section trough, said seal being outside said jacket.

ELMER K. HANSEN.

